Hello, Thanks! I had solved the problem some days ago, and it was actually related to your answer. First, I hadn't used push_struct_function() to allocate storage for my new function. Second, I wasn't calling finish_function() after setting my tree, so it would not be further compiled (just like your suggestion, since cgraph_add_new_function is called inside it). As I was inside the scope of main(), I also needed to save the function context with push_function_context(), call finish_function() and then pop the context back. Third, the flag DECL_EXTERNAL for my function was being set, so even though my tree was going to be further compiled, the definition for my function_decl was to be found outside file scope.
Now the problem is solved, but I still face an odd behavior: sometimes my function is output, sometimes not. Basically 50% of the times I compile my code, my function is simply not output. And when I try to debug gcc with gdb, it always fails. Any thoughts? Maybe I am missing something related to garbage collection or so... Not a clue. --- Rodolfo Guilherme Wottrich Universidade Estadual de Campinas - Unicamp 2013/7/22 Martin Jambor <mjam...@suse.cz>: > Hi, > > On Wed, Jul 17, 2013 at 04:52:30PM -0300, Rodolfo Guilherme Wottrich wrote: >> Hello there, >> >> Please disregard this message in case it doesn't fit here. >> >> During compilation of a C file, I need to be able to create a global >> function definition, with whatever a body I may have forged. I mean, >> the function is not going to be present in the source file and I got >> to create the respective tree structure so it can be later gimplified >> and further compiled like any other function present in the source. I >> would only need to create that function in case some OpenMP directive >> is encountered, so my latest and unsuccessful try to do so was to >> create the tree structures for a FUNCTION_DECL and, say, a variable >> declared inside the scope of that function, after the parsing of a >> #pragma omp parallel in c_parser_omp_parallel() in file c-parser.c. I >> followed and tried to re-create the steps I found in the function >> create_omp_child_function(), in file omp-low.c, and >> http://gcc.gnu.org/onlinedocs/gccint/Function-Basics.html#Function-Basics. >> >> I think maybe the problem is that my new function doesn't go under >> rest_of_compilation, therefore it is not gimplified and obviously no >> code for it is generated. > > it's a bit difficult to say without knowing what you are doing and at > what compilation stage you are doing it but perhaps you could try > calling cgraph_add_new_function on the new decl? Also try reading the > comment at the beginning of cgraphunit.c. > > Hope it helps, > > Martin > > >> >> Summarizing: I tried to forge a function in parsing time, but >> couldn't. What am I doing wrong, and how can one do such a thing? >> Maybe the problem is that I create no calls to that new function, what >> do you think? Anyway, I'm compiling with -O0, so I guess no >> optimization pass would remove my function just because it is not >> being used. >> >> Thanks in advance, >> >> --- >> Rodolfo Guilherme Wottrich >> Universidade Estadual de Campinas - Unicamp
